Vehicles are supplied with driver's side airbag modules; generally the driver's side airbag module is located in the center of the steering wheel. This is also the same location where a horn-activating switch has traditionally been mounted.
Various mounting mechanisms have been used for securing the inflatable restraint module to a support structure in a vehicle, such as a steering wheel or dashboard. In one known mounting mechanism, mounting bolts are provided passing from a rear of the support structure and threadably engaging nuts mounted on the inflatable restraint module. In another known mounting mechanism for a vehicle steering wheels sleeve members mounted to the inflatable restraint module and surrounding the mounting bolts may be forced into contact with a plate forming the supporting structure on a hub portion of the steering wheel to complete a circuit for actuating a horn.
Eventually, the horn-activating switch was adapted for mounting on the underside of the airbag module wherein the module was mounted in a “free floating” arrangement to allow the user to activate the horn by applying an activation pressure to the module and move the driver's side airbag module into a horn activation position. Such horn-activating switches react to a user-applied force to the cover in an effort to sound the horn. For example, and in such a system the entire airbag module moves as force is applied to actuate the horn.
Most original equipment manufacturers (OEMs) style their driver's side airbag modules and steering wheels by using a contoured gap between the two parts. This gap primarily allows the driver's side airbag module to move freely relative to the Class A surfaces of the wheel (free movement is required for a floating horn system). However, the OEMs also contour these gaps so that they contribute to the overall style and appearance of the driver's side airbag module and steering wheel assembly.
Once attached, the module is capable of movement through the application of a user-applied force wherein a horn circuit is completed in accordance with known technologies. The module is biased in a non-contact or open circuit position by a plurality of biasing springs. A current apparatus for a snap-in floating horn system uses the combination of three components at each point of attachment. The three components are a locking pin extending from the driver's side airbag module, a locking spring attached to the wheel, and a plastic insulator also attached to the wheel. These three components work in conjunction and can be arranged to create a two, three, or four-point driver's side airbag module attachment to the wheel. During module attachment, the locking pin goes through a slot in the insulator, displaces a locking spring attached to the insulator or the steering wheel, and locks into the wheel after the locking spring moves back to its original position thereby engaging a groove in the locking pin.
The current floating horn mechanism having a two point snap in attachment, for example, has many parts (e.g., 33) and assembly thereof involves using expensive assembly equipment and results in horn contact gap variations and driver air bag (DAB) cover to steering wheel (SW) fit variations and spoke gap variations as a result of stack height tolerances of the assembled parts. Accordingly, it is desirable to reduce the number of parts, costs, and horn contact gap variation, as well as DAB cover to SW fit and spoke gap variation. It is further desired to have a design that will be compatible with two, three or four point snap in DAB designs.